Coloration of materials containing cellulose esters



Patented Apr. 26, 1938 COLORATION OF MATERIALS CONTAINING CELLULOSE ESTERS James Arthur Wainwright and John Allan, Spondon, near Derby, England, assignors to Celanese Corporation of America, a corporation of Delaware N Drawing. Application May 15, 1936, Serial No. 79,928. In Great Britain May 24, 1935 4 Claims.

This invention relates to the production of ornamental efiects on materials.

Various methods are employed for the production of pattern eflects on textile materials. Thus, for example, a color may be applied directly to a material by printing and "fixed thereon by steaming or other suitable after-treatment. Again, the material may be colored all over and thenprinted with a composition containing a discharging agent for the ground color so that the coloration is destroyed in the printed areas.

According to the present invention, pattern effects are produced on textile or other materials containing a cellulose ester by applying in a 0 pattern a coloring matter or component having no amnity or small aillnlty for the cellulose ester and good aflinity for cellulosic materials, before or after saponifying the cellulose ester in a pattern which coincides only in part with the pattern in which the coloring matter or component is applied. When a dye component is used it is subsequently converted into a dyestufi on the material.

By this process the coloring matter or component is fixed in parts only of the pattern in which it is applied whereby a broken design is produced, or the design is in a deeper shade where the coloring matter pattern falls on a saponified area than where it falls on'an unsaponified area.

For the local saponificatlonoi the cellulose ester, a saponifying agent'ie. g. caustic soda) may be applied in suitably thickened preparations, which may contain swelling agents for the cellulose ester, and any other desired ingredients, by printing, stencilling, or other convenient method of local application, and the mateponents having a good aflinity for cellulosic materials and low aflinlty for cellulose esters under the conditions of application may be employed in the production of the pattern effects. Thus, for example, there may be employed direct cotton dyestufl's, chrome mordant printing colors,

or azo dye components which may subsequently be coupled on the material to form the azo dyestufl, -i'or example the sodium salts of enolic coupling components, e. g. p-naphthol, 2:3-oxynaphthoic arylamides, the diacylacetyl derivatives of aromatic diamines, or pyrazolones. Because of the great fastness of the colorations obtainable with sulphuric and other esters of leuco vat dyestufls, such for example, as those sold under the trade name IndigosoP', it is preferred however to'use these coloring matters for the formation of the colored patterns.

Thus, for example, pattern eflects in very fast shades may be obtained in accordance with the present invention by applying an esterifled leuco compound of. a vat dyestufi in a pattern to a locally saponifled cellulose ester material, so that only a part of the pattern falls on the saponifled area, anddeveloping the coloring matter without steaming. In many cases there is just suflicient fixation of the dyestufi on the cellulose ester for a shadow design to be obtained completing the broken design which appears where Dyestull Sec Indigosol Pink IR powder G Indigosol Brilliant Pink 138 powd r e lndigosol Red HR powder Indigosol Printing Blue IGG powder. Indigosol Printing Blue 13 powder. lndigosol HB powder Indigosol 04B powder Indigosol Violet AZB ov/den. Indlgosol Green AB powder.

Colmklndex No. 1176 and Supp.

p. G. Schultz, Farbstofltabellen,

7th Edition, lst Supp. p. 108. Color Index No. 1217, Supp. p. Color Index Sugp. p'. 43.

Schultz, arbstoiftabellen, 7th Edition, lst Supp. 109. G. Schultz, Farbstoflta lien,

7th Edition, 1st .Supp. p. 108. Color Index Supp. p. '43. G. Schultz, Farbstofltabellen,

7th Edition. lst Supp. p. 108. G. Schultz, Farbstofltabellen,

7th Edition, lst Supp. p. 108.

Color Index Supp. p. 43.

Color Index No. 1184, Supp. p

16. (-olor Index, Supp. p. 43. 4 G. Schultz, Farbsmlitabcllen. 7th Edition. 1st Supp. p. 108

tion to the dyestufl or dye component. .Thus,'

for example? it may contain thickening agents,

dyestuffs having affinity for cellulose esters and losic materials and good aflinity for cellulose tion without being in any way limitative.

ester materials, and coloring the cellulose ester component in a shade different from that produced on the saponified material in accordance with the'present invention.

Where esterified leuco vat dyestuffs are employed, agents adapted to give rise to oxidation of the dyestufiduring a subsequent treatment may be incorporated in the composition to be applied. Especial mention is made of agents such, for example, as sodium nitrite or a chlorate, e. g. aluminlum chlorate, adapted to exercise their oxidizing action under acidic conditions. Where a chlorate or sodium nitrite is employed, a small quantity of ammonia or other alkali is preferably also incorporated in the composition to prevent premature oxidation of the leuco compound. The oxidation may be assisted by the presence of oxidation catalysts, e. g. copper salts or ammonium or other vanadate, which are conveniently applied tovthe material before the application of the esterified leuco compound.

Any convenient method of local application may be employed for the application of the coloring matter composition. Thus, the compositions may be applied by printing, whether screen printing or printing 'withengraved blocks or rollers, or by, brushing or spraying through stencils. After application of the coloring matter or component the materials are subjected to suitable fixing or other treatments. For the development of an esterifled leuco vat dyestuff applied in conjunction with a chlorate or nitrite, the treated materials are dried at low temperatures and developed in an acid bath, e. g. a mineral acid bath containing sulphuric acid, and then washed, soaped, and again washed and dried. The esterified leuco vat dyestufi will be removed from the cellulose ester portions of the materials but fixed on the saponifled portions of the material. Where a direct cotton dyestufi is employed, a steaming or other fixing treatment may be applied, and the materials then washed to remove the dyestuff from the unsaponified material.

The effects produced in accordance with the present invention may be varied, for example by printing first with resist compositions so that the resist composition falls in part on an area wherein fixation of the coloring matter on saponified cellulose ester material would have occurred in the absence of the resist. chanical' or other resists may be employed. For resisting esterified leuco vat dyestufis a reducing agent, such, for example, as a hydrosulphite, may be applied locally to the materials, which will des'troy or neutralize the oxidizing agent and prevent the development of the leuco vat dyestuff color in the selected areas. Other effects may be obtained if the fabric treated in accordance with the present invention is a mixed material, containing a cellulose esterand some other type of fibre. Thus, for example, the materials may contain alternate cellulose ester yarns and cellulosic and/or cellulose ether or natural silk yarns.

The following examples illustrate the invenpartsare by weight:

For this purpose me- The Example 1 A cellulose acetate woven fabric is printed in a bold design with the following saponifying composition:-

\ Parts Caustic soda 15 British gum thickening (1:1)- 50 Glycerol 5 Water 30 and is then dried, washed well with dilute acid, washed to free from acid, and .again dried The printed material is then over-printed in a small design with the following composition:-

. Parts Indigosol Yellow HOG powder 6 ljndigosol Printing Blue IGG powder 2 Water 41 Thiodiglycol 3 Ammonia (10%) 5 Gum of tragacanth (8%) 40 Sodium nitrite 3' The printed materialois dried and then d veloped in an aqueous solution containing 25 005. 'per litre of 168 Tw. sulphuric acid at 60 C. and is then washed, soaped, washed again and dried. v A deep coloration occurs where the Indigosol print falls on the saponified area and a faint coloration where the Indigosol print falls on the unsaponified areas of the fabric.

Example 2 A woven fabric having a cellulose acetate weft and an intermittently saponified cellulose acetate warp is prepared with the following solution:-

, Parts Ammonium vanadate 1 Tartaric acid. 5 Water 94 and is then dried.

The treated material is then printed in a bold design with the following composition:

Parts Golden Yellow IGK powder 6 Wateri 46 Gum tragacanth (53%)-", 40 Tartaric acid (10% solution) 2.3 Aluminium chlorate (42 Tw.) 5

The printed material is then dried, hung in the air for about a day, and then well washed and dried.

- Having described our invention what we desire to secure by Letters Patent is:

1. Process for the production of pattern eifects on textile materials containing'cellulose acetate,

-which comprises saponifying the cellulose aceon textile materials containing cellulose acetate,

which comprises locally saponifying the cellulose acetate in a pattern, impregnating the material part only with the pattern in which saponlfication has been eifected, and allowing development of the coloring matter by the action of the chlorate to proceed so that a shadow efiect is obtained on the unsaponified portions of the material.

3. Process for the production of pattern effects on textile materials containing a cellulose ester, which comprises locally 'saponifying the cellulose ester and thereafter applying thereto an esterified leuco vat dye-stufi which has slight aflinity for the cellulose ester in a pattern which coincides in part only with the pattern inwhich saponiflcation has been effected and finally developing the coloring matter so that a shadow effect is obtained on the unsaponifled portions of the material.

4. Process for the production of a patterned textile fabric, which comprises applying to a cellulose acetate fabric containing in a pattern saponifled cellulose acetate, a pattern in an esteri- :fied leuco vat dyestufl which has slight amnity for the cellulose acetate, so that the pattern of the coloring matter coincides in part only with the pattern of the saponified cellulose acetate, and then developing the coloring matter so that a shadow eflect is obtained on the unsaponifled portions of the material.

JAMES ARTHUR WAINWRIGHT.

JOHN ALLAN. 

